The present invention relates generally to a one-piece forcible entry tool and, more particularly, to a one-piece forcible entry tool with a novel anti-rotation device which prevents the tool from rotating and dislodging from a door jamb or similar access blocking article during operation.
Portable forcible entry tools are well-known in the art and consist generally of a pair of feet, with one foot extensible in relationship to the other. Such tools are often used by law enforcement officials and fire department personnel to open doors or enter areas protected by locks. The tools may lave a separate pump or, alternatively, a pair of handles, one being stationary, with the other being movable in relationship to the stationary handle. The movable handle is connected to a hydraulic system which pumps hydraulic fluid into a hydraulic cylinder. The cylinder operates around a slide or similar structure connected to one of the feet. The foot which is not connected to the slide is connected to a frame, which houses the hydraulic cylinder.
Operation of the tool involves moving the feet into a closed position and forcing the feet between a door jamb and a door. The tool is inserted either manually, or by striking the strike plate with a hammer or other similar tool. The movable handle is then used to pump hydraulic fluid into the cylinder. As hydraulic fluid moves into the cylinder, it pushes the slide outward, thereby moving the moveable foot away from the stationary foot. As the two feet move apart, the door moves away from the jamb until the lock or other means maintaining the door closed is broken, or the door is open far enough to obtain access.
A typical problem associated with prior art forcible entry tools, is the tendency of the slide to rotate in relationship to the hydraulic cylinder as the feet press against the door jamb. The torque generated between the feet decreases the stability of the tool and may jar the tool loose from the door jamb before the door has been opened. In situations such as a burning building, where time is critical, crucial seconds used to move the feet of the tool back together and reinsert the tool between the door jamb and the door jamb could mean the difference between life and death.
To overcome the problem of the movable foot rotating in relationship to the stationary foot, guide bars are often employed which run parallel to the slide and are connected both to the frame and the movable foot. The addition of such guide bars rod not only increases the weight and bulk of the tool, but also decreases the ease with which the tool may be manipulated, thereby limiting the areas into which the tool can be placed. Furthermore, although such guide bar configurations add stability to the tool when the feet are relatively close together, the anti-rotation effect of the guide bars is significantly diminished as the feet are moved further away from one another. As the feet move farther apart, the torque on the feet begins to overcome the stabilizing effect of the guide bars.
Additional problems with prior art forcible entry tools are the intractability of the hoses used to transfer hydraulic fluid from the pumping mechanism to the extension mechanism and the additional weight added by external hoses and external pumps. The hoses increase the bulk of the tool, while exposing relatively delicate hydraulic lines to the possibility of snagging and puncture. The added weight and bulk of external bases and large anti-rotation makes carrying these tools difficult.
The difficulties encountered in the prior art discussed hereinabove are substantially eliminated by the present invention.